Limits of self-focusing using closed time-reversal cavities and mirrors-theory and experiment

Self-focusing through an aberrating medium with time reversal acoustic mirrors is discussed. The concept of a closed time-reversal cavity is introduced to analyze the basic properties and theoretical limits of the time-reversal process. The first step consists in an experimental measurement of the sound wave propagating from a source. In the second step, the goal is to focus an ultrasonic pressure field on the initial source position. The pressure field that propagates inside the time-reversal cavity resulting from the assumptions is computed. It is shown how the impulse diffraction formalism leads to a theoretical limit of the self-focusing process. The different effects that perturb the focusing process are analyzed. Theoretical results are compared with experimental results